As millions of Americans grapple with letters from their insurance companies notifying them that their policies have been cancelled despite President Obama's repeated promises over a five year period that it wouldn't happen, it's become clear that Americans have no reason to trust his word.

It also reinforces why there's no reason for the rest of the world to believe another famous pledge: "I have said that when it comes to preventing Iran from obtaining a nuclear weapon, I will take no options off the table, and I mean what I say."

Despite Secretary of State John Kerry playing footsie with Iranian officials in Geneva over the weekend, negotiations did not immediately yield an agreement on the nuclear issue.

But earlier, Kerry was touting a proposed agreement under which the West would agree to ease sanctions on Iran in exchange for basically nothing -- a promised six-month freeze in nuclear development from a country that has repeatedly violated international agreements.

As Israeli Prime Minister Benjamin Netanyahu said after meeting Kerry:

"The deal that is being discussed in Geneva right now is a bad deal. Iran is not required to take apart even one centrifuge. But the international community is relieving sanctions on Iran for the first time after many years."

But Obama's damaged credibility, not just on health care but also on allowing Syria to cross his red line without taking forceful action, sends a signal to Netanyahu, who must contemplate military action against Iran if its nuclear program progresses and America fails to act.

And it also sends a signal to the leaders of Iran, because only a credible threat of force will make them agree to abandon their nuclear ambitions.

When President Reagan followed through on his pledge to fire striking air traffic controllers in 1981, it showed the Soviets that he meant what he said.

Georgetown University Professor Joseph McCartin, who authored a history of the strike, wrote in a New York Times op-ed that, Reagan's "forceful handling of the walkout, meanwhile, impressed the Soviets, strengthening his hand in the talks he later pursued with Mikhail S. Gorbachev."

Obama, addressing those with canceled health insurance, told NBC's Chuck Todd Nov. 7, “I am sorry that they are finding themselves in this situation based on assurances they got from me."

Netanyahu can't allow millions of his citizens to live under an existential threat because he trusted Obama's assurances.